public class Demo10 {
    private static boolean isRunning = true;

    public static void main(String[] args) {
        // boolean isRunning = true;

        Thread t = new Thread(() -> {
            while (isRunning) {
                System.out.println("hello thread");
                try {
                    Thread.sleep(1000);
                } catch (InterruptedException e) {
                    throw new RuntimeException(e);
                }
            }
            System.out.println("t 线程已经结束了");
        });
        t.start();

        try {
            Thread.sleep(3000);
        } catch (InterruptedException e) {
            throw new RuntimeException(e);
        }

        // 3s 之后, 主线程修改 isRunning 的值, 从而通知 t 结束.
        System.out.println("控制 t 线程结束");
        isRunning = false;
    }
}